As mobile communications systems develop, the systems can provide increasingly high quality of service. To maintain long-term competitive advantages of the 3rd Generation Partnership Project (3GPP) for mobile communications, and further improve system spectrum efficiency and a user throughput, carrier aggregation (CA) is introduced. Carrier aggregation refers to that user equipment (UE) can simultaneously use multiple cells to perform uplink and downlink communication, to support high-speed data transmission.
Carrier aggregation may be intra-base station carrier aggregation or inter-base station carrier aggregation. Intra-base station carrier aggregation refers to that for one UE, aggregated serving cells all belong to a same base station. Inter-base station carrier aggregation refers to that for one UE, in multiple serving base stations, one base station may be a primary base station (Primary Base Station or Master Base Station), or is referred to as an anchor base station, and another base station may be a secondary base station, where the primary base station is used to perform more control functions. In Long Term Evolution (LTE) or LTE-Advanced (LTE-A), the primary base station may also be referred to as a Primary eNB (PeNB) or a Master eNB (MeNB).
After the inter-base station carrier aggregation is introduced, how to design a measurement mechanism is a problem that needs to be resolved in the present invention.